http_server followed by a trailing slash

File usage advice to use --http_server http://localhost/opencart (without trailing slash) and the CLI installer concatenate other directories without adding "/" before the concatenated directory thus saving wrong URLs in config files as eg.: http://localhost/opencartadmin
modification update to account for offset
more modification system changes done
minor update
Fix for the cache's file driver - added some protections to race conditions.
Merge pull request #1446 from Martynas-P/master

Fix for the cache's file driver - added some protections to race conditions.
Update install SQL script

Add extra custom field columns for oc_order table.
fix for

https://github.com/opencart/opencart/pull/1431
Merge branch 'master' of https://github.com/opencart/opencart
added a api user page
more api work done
https://github.com/opencart/opencart/issues/1454
https://github.com/opencart/opencart/issues/1439
https://github.com/opencart/opencart/issues/1439
Added blocking writes to the File driver.
renamed variable.
Merge pull request #1459 from Martynas-P/master

Added blocking calls to the File driver.
Added Selenium tests; Testing bootstrap.php use live database's details; Renamed classes of unit tests.
Remove stray s from td tag
more api work done